An effective measure for reducing the fuel consumption and CO2 emissions of motor vehicles has proven to be a reduction in swept volume in conjunction with supercharging of the internal combustion engine, so-called downsizing. In interaction with a direct injection of fuel, it is possible here to generate considerable potential for the reduction of fuel consumption and CO2 emissions. This is achieved in particular by means of reduced internal friction, by means of a shift of the operating point of the internal combustion engine into higher load ranges, and not least by means of a reduction of the weight of the internal combustion engine as a result of smaller swept volumes and/or a reduced number of cylinders. For the most effective possible supercharging of an internal combustion engine, so-called charge-air cooling is prior art.
FIG. 1 shows a schematic diagram of a motor vehicle having a supercharged internal combustion engine 10, wherein the internal combustion engine 10 in FIG. 1 has two cylinder banks or cylinder groups 11 with in each case three cylinders 12. Each cylinder group 11 is assigned in each case one exhaust-gas turbocharger 13, wherein each exhaust-gas turbocharger 13 comprises in each case one turbine 14 and in each case one compressor 15. Exhaust gas flowing out of the cylinders 12 of the cylinder groups 11 is expanded in the turbines 14 of the exhaust-gas turbochargers 13, wherein energy gained here is used to drive the respective compressor 15 of the respective exhaust-gas turbocharger 13 in order to compress charge air, which is conducted via an air filter 16, in the compressors 15 of the exhaust-gas turbochargers 13 and to conduct said compressed charge air via charge-air coolers 17 such that the charge air compressed in the compressors 15 is thereby cooled in the charge-air coolers 17. In FIG. 1, each exhaust-gas turbocharger 13 is assigned a separate charge-air cooler 17, wherein the charge air exiting the charge-air coolers 17 after having been cooled is supplied via a common throttle flap 18 and via a common collector 19 to the cylinders 12 of the cylinder groups 11. Accordingly, in FIG. 1, the charge-air flows are merged downstream of the charge-air coolers 17 and upstream of the throttle flap 18.
It should be pointed out at this juncture that it is likewise already known from the prior art to provide a separate collector for each cylinder bank 11, wherein then the cooled charge air exiting the charge-air coolers 17 is supplied to the respective collectors via separate throttle flaps.
In motor vehicles known from practice which have a supercharged internal combustion engine and a plurality of charge-air coolers, the individual charge-air coolers are formed as separate assemblies. This can result in installation space problems if charge-air coolers formed as separate assemblies are to be integrated into a motor vehicle with limited installation space. Furthermore, if a plurality of charge-air coolers formed as separate assemblies are integrated into a motor vehicle, there are resulting disadvantages with regard to the weight of the motor vehicle and with regard to the assembly time required for assembly.